Phone numbers in Spring Valley, Illinois
Spring Valley has 4 phone prefixes in area codes 779, 815.
Biggest holders: Frontier, T-Mobile (including Sprint), Peerless Network Of Illinois. This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 25%
- Local phone company 50%
- Internet / business phone carrier 25%
Every prefix in Spring Valley
Search the first six digits of a number in this list. If it's here, the number started in Spring Valley with the carrier shown. If it isn't, check the Illinois page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 779-349 | T-Mobile (including Sprint) | Mobile carrier | 2022 |
| 779-717 | Peerless Network Of Illinois | Internet / business phone carrier | 2015 |
| 815-663 | Frontier | Local phone company | – |
| 815-664 | Frontier | Local phone company | – |
Most prefixes are pooled: the 10,000 numbers in each are handed out in blocks of 1,000 to different carriers, and people can also take their numbers to another carrier. So the carrier shown is where the prefix started, not a guarantee about any one number. Source: NANPA central office code records, 2026-10-10.